How to Make Your Own Plasma Cutter....




Posted in WorkshopTools

Introduction: How to Make Your Own Plasma Cutter....

About: Hi I'm Joe and welcome. I love to make Homemade Tools & More. I will have many things to put on the instructables for you to gander at. I hope you enjoy there educational value and have fun. Come se my h...

Check out new video of the Plasanator on

This Ebook is designed for Guys and Gals who like to create tools and machinery.

I hope my Ebook gives you hope that no matter how hard a project may seem, keep plugging away until you finish and you will succeed.

I spent 3 years putting this together and now finally all my hard work and research has paid off.

I studied diagrams from commercial venders, but to no luck. They tend to leave a lot out – on purpose - so it’s hard to reproduce their design. I’ve see different attempts at people making their own on You Tube and other sites, but what a death trap. Messy water resistors and wiring like a darn Christmas tree.

So I began reading books and articles on their workings and took my home schooled-knowledge of electronics to build my own plasma cutter. I was determined; failure was not an option.

I started by collecting parts from old microwaves, stoves, water heaters, air conditioners, car parts and more in the hopes of creating a low budget way to create a plasma cutter for myself. I mounted it all on a simple piece of scrap wood; well it’s scrap wood now. We, didn’t need that table anyway (shhhhhhh don’t tell the wife).

Then one day it all came together. I hit the power switch, placed the head to the metal, started the arc, felt the air kick and then a second hard kick (the current being drawn into play). Then BAM, it was slicing through quarter inch steel like a hot knife through butter.

How sweet it sounded! I felt the amazement of completing a project that I just couldn’t let go of.

So, take your time, enjoy and be safe.

The Plasaman

Step 1: Assembly

When I started assembling my cutter, I began with taking a good look at my parts. As shown in Section 5 and Section 6, my parts are laid out so I can begin checking off from my parts list. Once this was accomplished, I would study each the parts pictorial to get familiar with each part/component and they would be placed.

The next step was to study my schematic and create a layout diagram. My board layout diagram is the most valuable piece in the building, repairing, and modifying process of my cutter.

As I began mounting my parts, I organized my board into four sections. Those sections are Power Control, High Current DC, Low Voltage DC and High Voltage Arc Start.

Power Control
3KVA step down transformer and contactor. The transformer is mounted off board because it is big and heavy, as you can see in Section 13. The contactor became my first part on the board. I wired it so when the head trigger is pressed, it turns the contactor on and allows my DC components to come on line. Then I began with my next system, High Current DC.

High Current DC
Bridge Rectifier
Large Capacitors
Reed Switch (which I used as a current sensor), what it does is allow the high voltage arc system to fire and as soon as high current starts to travel to the head and cutting starts it shuts down the high voltage arc system while cutting since it’s not needed at this point.
If you lose your fire it restarts the arc and gets you going again automatically.
My next system was placed on board.

Low Voltage DC
The low voltage DC components are mixed with power switch and 120 volt terminals.
Power Switch
120-volt terminal blocks
12 volt transformer
Low voltage bridge rectifier
Auto relays
Terminal strip, 4 position is all I needed but 5 position was what I had in my toy box.

High Voltage Arc Start
Microwave capacitor or run capacitor, a household dimmer switch rated for 15 amps. A Ford or Chevy ignition coil. I used the Chevy on this cutter. As you can see, I have terminals to all parts that get an external connection outside of their system so all I have to do is run a piece of wire in-between. Now look at the pictorial of board mounted parts in Section 11. It shows all the wires on the board, but here you can see all terminals and parts mounted, as I wanted. When wiring all my components, I used my Chevy board layout diagram to run my wires.

I checked and re checked all wires before mounting external parts. If you go to the final wiring section, you will also find pictures of my rigging of these parts. I could have done it many different ways, but this is what I chose at this time.

It took me about 3 hours of procrastination to finally assemble it all. You know how it is on a project, once you are ready with all your parts, your mind starts giving you a million ways of doing something. And, at last you just pick a way and go with it.

Once I got it all together, I connected my air tank hose and put the pressure setting at 28 for a safe point to start. I fired it up and BAM - that baby didn’t need any more adjusting. It was cutting!

You can imagine all the relief and pride I felt when the Plasanator started kicking ass. Yea, I said it Kicking Ass Baby. Oops Wife just told me I need to stop, hee hee and for all you creators – ah ah ah ahhhhhh.

I hope you enjoyed riding along with me in my journey.

Take care and be safe.

The Plasmaman

Step 2: Parts List

Parts List

Step 3: Warning Warning

Step 4: Schematic

Chevy Pictorial Schematic

Step 5: Another View

Step 6: Another Schematic to Looksy At

Step 7: Board Lay Out

Now this is to demenstrate how I set it up before putting it in a case configuration.
So dont think you would leave it like this for it would be to dangerous to do so.

Step 8: Transformer I Used

Its a control transformer I got off ebay for 50 bucks.
It's 220 to 120 3kva 25 amps and works great in power isolation.

Step 9: Transformer Connected to Board Terminals.

Step 10: Power to Contactor Terminals

These are the contactor terminal conections on the transformer side and then the contactor to large bridge rectifier connections.
Also you will see Bridge rec to Capitor connections and how they are connected.
This is your Main Current set up.

Step 11: Reed Current Sensor

Step 12: Low Voltage Side

Step 13: Relay Connections by Color

Step 14: Chevy HV Transformer Connections

Step 15: Arc Tip Assembly to Head

Step 16: Head Air Coupling

here is where you will connect your air line to your head if you dont have a fitting to do so then hook to board connections.

Step 17: Air Filter/ Element and Solinoid Hook Up View

Just showing temp hook up.

Step 18: Final Power Connections

Ok now you can put all your final connections together and keep going over your schematic to double or triple check everything.

Step 19: Extra Photos of Past Cutter Projects

Here are some photos of past cutter projects for you to enjoy.
Now remember that you will need to put in a case for safty.
It can be would metal or plastic just enclose it.
My photos are in a testing stage and that is why you see them exposed.
The photos of the red cutter was a china one that burnt up on my neighbor and I ripped out the guts and replaced it with my design.
He just loves it.
The black box on side is the housing for 2 elements to draw more current.
You will also see here some other designs where I used a chevy control module as the hv arc start and my first plasma cutter on test stand using stove coils as current resistors.
Have fun and be safe ya'll. Joe

Step 20: Plasanator 3's First Cut

Goto link and watch it's first cut while listening to the mission impossible song.
Thanks for stopping by and God Bless.

2 People Made This Project!


  • Spotless Contest

    Spotless Contest
  • Microcontroller Contest

    Microcontroller Contest
  • Space Challenge

    Space Challenge

We have a be nice policy.
Please be positive and constructive.


6 Questions

Hi Where did you get a 15 amp dimmer switch all I can find is a 600 watts which is only 5 amps?

Thanks Barry

Hi I am confused about hooking up a wire from the AC side of the rectifier to the second cap on the negative terminal won't that damage the cap as they work on DC current?

Thanks Barry

No it won't it acts as a voltage doubler circuit.

Hi I almost have all of the parts required for the build but I was thinking of using 220 VAC for the power what are the required changes to your great e book in order to do the upgrade and when using the heater elements for a resistor is there any heat generated ie: is a heat sink required?

Thanks Barry

Good night, thank you very much for the answers, I already have almost all the parts you would need, I only lack the capacitors I do not know where to find !!

Thanks again

Best regards

go to ebay they have tons of them

Now I'm the bit confused, do I have to remove the wire that goes to the center of the capacitors, or not?

Thanks again.

Best regards

as long as your caps are 350 volt or bigger leave it.

Good morning, I'm very interested in this project, but I have some questions,
Is it possible to make the 220v circuit instead 120v?
I wish you could help me.

Best regards

Filipe Monteiro

The third diagram is wired for 220 they are both the same except going to contactor and 120 going to coil hv circuit

1 more answer


Yes, you only must remove the voltage dobler wire. It's the wire that come out from the diode bridge to the center of capacitors.


Sir some problem in plasma cutter every two or three time use then short a rectifier I use rectifier 50amp. 600volt x 3 pies

1 reply

Some of the cheapy rectifiers are junk get you a 90 to 120 amp rect and you should be good to go.

My isolation transformer made of a old welder machine. It will be capable to supply 40A at 220vac. I will try to remove the heater element an include a pwm controller. For HV i designed a coupling coil to isolate the HV side of the high current side. Soon as i test i will publish here. Wish me luck!

WhatsApp Image 2018-02-18 at 22.24.02.jpeg
1 reply

Be nice to see it. good luck God speed

Thanks great work Good explanation There is only something I did not understand

Chevy HV Transformer Connections 14 Thank you
4 replies

If it's about the hv lead coming off the bolt to capacitors and lead going to torch head ? it's set up this way to cause arc to electrode when trigger is pressed.

Hi Saraa, if it's the bolt on it and how it's mounted , you can just solder 10 guage wire directly to coil spot.

Don't need bolt set up at all. this was first time using this kind of coil and later found out the flat spot wasnt aluminum but was able to be soldered to.

I do not understand How much is needed from the current I have coil Bipolar 8 kv Per pole Is it enough and thank you

it will be great should give you about 36 amps and you will want to run at about 25 amps for 1/4 inch cuts and if just thin sheet metal 16 to 18 amps will be great.

thanks for your wonderful work。

but there is a QUESTION!

what‘s the heater element for ?in this design。

hope anyone could help me with that question, thanks!

sorry , i am not good at electric thing 。

2 replies

It is a load resistor which pulls your current need to cut

it adds resistance to the circuit.

Thank you for sharing your knowlegde. I would like to make my own plasanator but the step down transformer is very expensive to bought it. I have a transformer rescued from a old stereo. Its marked as +63v / -63v out, 120 volt in. I supose 120v in - 120v out . Do you think I can use it? I want to cut carbon steel 18 gage with a CNC machine I made. here is a video

Thank you

Abraham Montemayor

Monterrey, MX.

2 replies

For 18 gauge it will work great. great video

hi And it all shuts Abraham I just use mains since I run it on a contactor.
Release trigger an all is shut down.
I never had one problem.
Your t former wont work.

Would like to build this as a 220 volt unit. I understand that I wont need the step down(up) xformer, and will need two heater elements, also a double pole main power switch. Are there any other changes that will need to be made to the circuit? also, you don't specify if the reed switch is NO or NC. From your description of the circuit, I'm assuming NC. Correct? Thanks for an interesting project!

2 replies

It is nc because you want it on until current flows then it opens to turn off high voltage arc.

That is correct and good luck have fun. Joe

Hello; Anyone needing some of these parts I have alot of those items

1 reply felix in kenya.and yes am interested to have some parts.